Metallic piston-packing



(No-Model.)

0. ROGERS.

METALLIC PISTON PACKING.

No. 398,177. Patented Nov. 20, 1888.

X s 8 F 7 thereon.

JIINITLED STATES PATENT Erica.

CHARLES ROGERS, OF ALLEGHENY, PENNSYLVANIA.

M ETALLIC PISTON-PACKING.

SPECIFICATION forming part of Letters Patent No. 393,177, dated November20, 1888.

Applieat-innfiled May 81, 1888. Serial No. 275,546. (No model.)

To aZZ whom it may concern.-

Be it known that 1, CHARLES ROGERS, residing at Allegheny, in the countyof Allegheny and State of Pennsylvania, a citizen of the United States,have invented or discovered a certain new and useful Improvement inMetallic Piston-Packings, of which improvement the following is aspecification.

My invention relates to certain improve ments in metallicpiston-packings and bullrings. Heretofore packings of the abovecharacter have been made without any provision for releasing the leakagesteam which accumulated beneath them. I propose to perforate thesepackings and permit the steam to come between the outer surfaces of thepackings and the wall of the cylinder. I facilitate the passage of thesteam to these perforations by turning grooves around the innercircumference of the packings. I furthermore perforate the bull-ring andcut in it certain channels, all of which will be more fully describedbelow.

The results attained by my invention may be summarized thus: first, areduction of friction and consequently of wear of the bearing surfacesof the packings, the bull-ring,and the walls of the cylinder; second, asteam-lubrication of all bearing-surfaces; third, floating thepiston-head, by which wear on the seat is diminished.

In the accompanying drawings, which make part of this specification,Figure l is a side elevation, broken away, of an ordinary pistonheadfitted with my improved bull-ring and packings. Fig. 2 is a like butenlarged view of the upper portion of Fig. 1. Fig. 3'corresponds withFig. 2, except that the bull-ring is omitted and a spring-ring used.Fig. 4' is a face View, broken away, of a spider or skeleton piston-headand the bull-ring fitted Fig. is a perspective view, but necessarilyinverted, of a section from the lower half, respectively, of thebull-ring, one packing, follower, and piston-head.

My inventionis applicableto all pistons using metallic packings orbull-rings, and the piston-heads shown in the drawings are merelyillustrative.

Fig. 1 shows a familiar form of piston-head, 1, having a bull-ring, 2,fitted thereto in the usual manner. The bull-ring 2is held rigidly inplace between the angle of the head 1 andthe follower 8, which issecured by screws 9. In the raised center of the bull-ring holes aredrilled of any desired shape and size. These perforations preferablyoverlap, that the wear on the bearing-face of the bull-ring may beequalized. The function of these perforations will be explained later.Grooves 3 3 and 3 3 are turned clear around the bull-ring 2 on bothsides of and at the base of its raised center. These grooves are bestseen in Fig. 5. The perforations on the lower half, or nearly all thelower half, of the bull-ring 2 communicate with these grooves 3 3 and 33 by means of the oblique channels 4 4. (Seen in Fig. 5.) Gross groovesare also cut at regular intervals in the circumference of the bull ringand on either side thereof, as shown in Fig. 5. Packing-rings 5 5 and 66 are loosely fitted over the bull-ring. They are free to move up anddown and therefore slightly from right to left. These packings are alsoperforated and desirably with overlapping holes for equalization ofwear. The number, size, shape, and relative position of the holes may bevaried as circumstances demand. To insure a proper distribution of steamto these perforations in the pack ings, I turn a series of innercircumferential grooves in the rings, as clearly seen at 7 77 in Fig. 5.

Fig. 3 shows similar packing-rings used with a spring-ring, 12. Thisspring-ring is perforated at suitable intervals to make connection withthe grooves of the packing-rings. It is of course indifferent whetherthe grooves are turned in the packings or in the bull-ring. It isapparent also that the grooves and perforations heretofore mentioned maybe cast, if wished.

The action of the steam on the packing rings in my device will be asfollows: As the packing-rings 5 5 and 6 6 do not fit closely against theangle of thepiston-head 1, or against the follower 8, the leakage steamwill pass down beneath the packings, and will then be distributed by thegrooves and cross-grooves to the holes in the packings, so that thepressure on the inside and outside of the packingrings will be nearlyequalized, effectually pre venting the packing from binding in thecylinder from an unrelieved pressure on the inside of the packing, whichfrequently occurs in the use of the ordinary packing. Moreover, theouter surface of the packing will be uniformily lubricated to a certaindegree. It is apparent that thesame effect will be produced when thepacking-rings are used with the spring-ring 12. (Shown in Fig. 3.)

The action of the steam on the bull-ring will be as follows: Since theperforations in the upper half of the bull-ring are ,not drilled throughto the distributing-grooves, these perforations will act simply aslubricatingpockets to receive and give out the leakage' steam, which mayenter them from the packing-rings on either side.

Theperforations on thelower half ofthe bullring being in communicationwith the steamdistributing channels 3 3 and 3 3 perform the importantand novel function of discharging steam into the perforations in thelower half of the bull-ring, which will there generate a pressuretending to float the piston'head and prevent excessive wear of the seatand head. In other words,the piston is supported, raised, or buoyed upby the steam-pressure beneath it. The various distributing-grooves maybe 'omitted, but the stream will not then be so satisfactorilyequalized. An additional advantage in the use of the perforations isthat their area very considerably subtracts from the actual area of thebearing-surfaces, thus materially reducing the friction in the cylinder.

Having thus fully described myinvention, I claim 1. Metallicpacking-rings having rows of independent perforations drilled therein toreduce the bearing-surface of said packingrings and to equalize thesteam-pressure on the outer and inner surfaces of said rings, allsubstantially as and for the purposes described.

2. The combination of metallic packingrings having rows of independentperforations drilled therein, and a perforated spring-ring, allsubstantially as and for the purposes described.

3. A bull-ring having pockets drilled in its upper and outersemi-circumference and perforations in its lower semi-circumference,extending from steam-distributing grooves to the exterior of thebull-ring, all substantially as and for the purposes described.

In testimony whereof I have hereunto set my hand.

CHARLES ROGERS.

\Vitnesses:

WILLIAM BEAL, WILLIAM L. PIERCE.

